Re: [PATCH] arm: mediatek: fix secondary CPU boot on Thumb-2 kernels with Clang

[Arnd Bergmann]

On Thu, Jul 23, 2026, at 11:15, Akari Tsuyukusa wrote:
> On Wed, Jul 22, 2026 at 02:03:31PM -0700, Nick Desaulniers wrote:
>> On Wed, Jul 22, 2026 at 10:25 AM Akari Tsuyukusa <akkun11.open@xxxxxxxxx> wrote:

>> Can you perhaps help test/verify that Akari?
>
> I tested your suggested patch and confirmed that it fixes the issue.
>
> Device: Lenovo YOGA Tablet 10 (Wi-Fi) (MT8125)
> Toolchain: Clang/LLVM 22.1.8-2 (cachyos-v3)
>
> Tested-by: Akari Tsuyukusa <akkun11.open@xxxxxxxxx>
>
> Can you send your fix as PATCH?
> I think your approach is better than mine.

I think we should wait for the llvm issue to be resolved first, to
document whether this is considered a bug in the kernel or the
assembler, and to see if any other kernel code may be affected
by the same thing.

Looking around other .S files, I see the same
pattern in stext(), cpu_resume_arm(), mcpm_entry_point(),
all of which start in arm mode but end in thumb.

     Arnd